Compass-altimeter.



K. SMITH.I

COMPASS ALTIMETER,

APPLICATION man Dac. a5. |916.

mmwm, mmm M. 26,191@ 5 wmNEs'sEs -INVENTOR KAN saniert-or PORTLAND,cancion.

COMPASS-ALTIMETER.

Specification of Letters Patent. application inea December i5, ieie. iserial no. 137,278.

ratenteii rei. saisie.

(DEDICATED T0 THE PUBLIC.)

To all whom t may concern: i

Be it known that I, KAN SMrrri, a citizen of the VUnited States ofAmerica, and an employee ci' the Department of Agriculture of the saidUnited States, residing `at Fort land, Uregcn, (whose post-ofliceaddress is y c/o 429 Beck Building, Portland, Oregon,) have invented anew and useful Improvement in Compass-Altimeters.

This application is made under the act of March 3, 1883, chapter 143 (22Stat., 625) and the invention herein described and claimed may be usedby the Government of the United States or any of its oiiicers oremployees in the prosecution of work for the Government, or any personin the United States, without payment to me of any royalty thereon.

My invention relates to a compass altimeter. The object of my inventionis to provide an instrument for disclosing readings of vertical anglesin connection with a compass in ordinary and topographic surveys, andwhich at the same time is inexpensive and simple in construction, andwhich coinbines sights for azimuth and vertical angles. The instrumentcomprising` my invention is designed to be used attached to a standardcompass, supported onda Jacob staff, tripod or traverse board. By slightchange in construction it could be adapted for use with any compasshaving long sight varies of equal length that will meet iiian acuteangle above the compass box, or with a sight alidade `with similar sightvanes. No alteration of the compass parts is required so that byremoving the attachment the compass is ready for instant use in theordinary way.

There are no detachable parts to ecome misplaced or lost. With ordinarycare there are no adjustments required and by simpleness of constructionnone to be made. Tts movements are independent of the compass and,therefore, will operate regardless of the levelness of the latter withinnot unreasonable limits. i

My invention consists in the combination and arrangement of parts, aswill be hereinafter more fully described, shown in the accompanyingdrawings, wherein, v

Figure 1 is a side elevation of the instrument; y

Fig. 2 `is a plan View of cross hairs used in the sight tube;

standards, sockets, etc. Y

Fig. 3 is a rear View of instrument;

Fig. 4c is a rear view of standards, socket, etc.;

Fig. 5 is a detailed sectional View of Fig. 6 is view of pendulum;

Fig. 7 is sectional view of pendulum weight, etc.

Referring to the drawings, A represents a pair of standards with socket,B, at their bottom for receiving the sight vanes, C, ot' compass,`D,and, by trunnions, E, supporting a sight tube, F. This tube has apinhole peep-sight, G, at one end and cross hairs, H, at tlie other end.This tube has on one side a vertical arc, I, of 180o with centercoincident with the center oit' the tube, F, and has a vertical motionof approximately 1200. The arc, I, may be graduated as desired orpreferably is graduated by one-liall' degrees both ways from 0o to 65,as shown at a Fig. l, and also has a separate scale of graduations inpercentages of slope both ways from 0% to 175%, as shown at l) Fig. 1.Supported by small pivots, ,in the outer ends of the trunnions, E, is aforked pendulum, K, swinging free over the face of the vertical arc, T,and having at its lower extremity a pair of indices, L, registering` onthe graduations referred to. A tension spring, M, is attached to one ofthe standards, A, to hold the tube, F, in a iirm but movable position.The pendulum, K, also has a weightV or plumb-bob, N, to improvesteadinessV and counteract disturbances by wind. This weight, N, issuspended between the sight vanes, C, and inv rear of the vertical arc,T, and has suliicient clearance to avoid all friction with the latterand interference by the sight vanes, C. The line of sight through thetube, F', is pan` allel to the line of sight of the compass varies, C,and to the edges of the square compass base, so that when using theinstrument a sight is taken through the sight tube only, with the crosshairs, H, centering` on the object. The azimuth is then read from thecompass needle in the usual manner and the vertical angle is read directfrom the vertical arc as with a transit. The compass with the altimetermay be used as an alidade in the usual way.

From the foregoing, it is thought that the construction, operation andmany advan- .tageslof the'herein describedk inventionv will Abe apparentto those skllledintheart, Withkout further description,` and it willbeun` derstood that various changes in the size, shape,V proportion, andminorV 'detailsf construction may be resorted to Without departing fromthe spirit or sacriicing any of the advantages of the invention. l -V AHaving thus described my invention, I claim: i' v Ay compass altimeterattachment, comprisi ingY a supporting member provided With socketsadapted to receive thesight vanes of a surveyinginstrument, a sightingdevicev Copies'of this patent'V may be` obtained for KAN SMITH.

Witnesses: R. H. ROBERTSON,

CHAS. J. KRAEBEL.

ve cents each, by'addressing the Commissioner o! Patents,

Washington-D. C.

